A world championship is generally a sports competition open to elite competitors from across the world, representing their nations, and winning such an event will be considered the highest or near highest achievement in the sport or contest.

The title is usually awarded through a combination of specific contests or, less commonly, ranking systems (e.g. the ICC Test Championship), or a combination of the two (e.g. World Triathlon Championships in Triathlon). This determines a 'world champion', who or which is commonly considered the best nation, team, individual (or other entity) in the world in a particular field, although the vagaries of sport ensure that the competitor recognised at the best in an event is not always the 'world champion' (see Underdog).[citation needed]

Certain sports do not have a world championship, instead they may organise a World cup competition, or they may organize both. Often, the use of the term cup or championship in this sense is just a choice of words. Some sports have multiple champions because of multiple organizations such as mixed martial arts, boxing and wrestling.[citation needed]

Certain sports do not have a world championships or a world cup as such, but may have one or several world champions. Professional boxing, for example, has several world champions at different weights, but each one of them is decided by a "title fight", not a tournament.[citation needed]

A certain number of sports hold world championships or world cups which are overshadowed, in terms of prestige, by the same events in the Olympic Games, the most prestigious multi-sports event.[citation needed]

Finally, certain professional sports do not have a world championship or world cup, but rather hold a series of events recognised as the elite level in their field (e.g. tennis has a series of four Grand Slam events recognised as the pinnacle of the game, in addition to key team events, world tour finals and the Olympic Games, but no world championship or world cup).